Klystron tuner



1 Aug. 17, 1954 c, w, DAV|5 2,686,890

KLYSTRON TUNER Filed Jan. 15, 1946 FIG. 2 fim 11% I5 INVENTOR CHARLES W. DAVIS BY Wq ATTORNEY the velocity modulated Patented Aug. 17, 1954 2,686,890 KLYSTRON TUNER Charles W. Davis, Framingham,

by mesne assignments, to the America as represented by the Navy Mass, assignor, United States of Secretary of the Application January 15, 1946, Serial No. 641,348

6 Claims. (01. 315-5) This invention relates to a tuning device, and more particularly to such cavity of electron tubes of the velocity modulated type.

While cavity tuners for electron tubes such as electron tubes of the reflex Klystron type have heretofore been constructed, such tuning devices have proven unsatisfactory due to complication of structure, and especially due to fbacklash and inaccuracies in tolerances causing play and lost-motion in such tuners.

An object of this invention is to provide a mechanical tuner for type. i

Another object of this invention is to provide a mechanical tuner for changing the alignment of certain elements within electron tubesof the velocity modulated type by applying stress to the outer surface of the envelope of such tubes.

Still another object of this invention is to provide a mechanical tuner of the. class described having a minimum of lost motion due to backlash. Other objects and advantages of this invention as well as its construction, arrangement, and operation, will be apparent from the following specification taken in connection with the following drawing in which:

Fig. 1 is a perspective view of a tuner constructed in accordance withthe principles of this invention.

Fig. 2 is a side view of the tuner shown in Fig. 1 having an electron tube mounted therein.

Fig. 3 is a side view partially in section illustrating the details of thetuning cavity of an electron tube to betuned.

Fig. 4 is a plan view of one of two similar clamps used to mount a tube to be tuned to the tuning device shown in Fig. 2.

Electron tubes of the velocity modulated type such as reflex Klystron tubes are well known to those skilled in the art. Such tubes are commonly tuned to a desirable frequency of operation by varying the dimension of the resonant cavity of the tube. Referring to Fig. 1, there is shown a tuning mechanism for accomplishing the above result comprising a U-shaped spring plate having openings 1 l and I2 drilled therein for insertion of the tube constructed of two sections operatively connected by a resonant cavity. A clamp 13 is mounted on the upper portion of spring plate I0 in order to fixedly secure the upper portion of the tube thereto. A second clamp I4 is mounted to the lower portion of spring plate In to fixedly secure the lower portion of the tube thereto. An

to be tuned. Such tubes are a device for tuning the L-shaped rocker arm lever I has the lower surface thereof placed on a suitable fulcrum It as shown. A set screw [1 threadably mounted in the upper portion of spring plate It provides a course tuning control and maintains a constant pressure upon the surface of the base of rocker tuning electron tubes of tube.

arm l5. In this manner, the vertical portion of the rocker arm is forced against a thumb screw 18 threadably mounted on a boss l9 secured to the lower portion of spring plate I0. A Klystron tube mounted in a tuning device as described is shown in Fig. 2.

In Fig. 3, there is shown the resonant cavity of a standard Klystron tube 2!] illustrating the features of the resonant cavity in detail. As shown, the resonant cavity 2| consists of a chamber enclosed by a pair of diaphragms 23 and 24 extending across the diameter of the The tuning mechanism constituting this invention is arranged to vary the spacing of surfaces 25 and 26 of the resonant cavity in order to vary the frequency of operation.

Referring to Fig. 4, there is shown one of two similar clamps l3 and I4 of Fig. 2 in detail. The clamp comprises two sections 21 and 28 which, when assembled, enclose an opening 29 to receive the tube to be held in place. A pair of screws 30 and 3| operate to draw section 28 around the tube in a clamping manner.

In operation, .the Klystron tube is placed in the tuning mechanism as shown in Fig. 2. Clamp i3 is securely fixed to a metallic flange 32 on the upper portion of the tube. In like manner, clamp I4 is securely fastened to the lower portion of the tube so that upper portion of the tube is fixedly secured to the upper portion of plate Ill, and the lower portion of the tube is securely fastened. The relative spacing of the upper and lower portions of the plate In may be varied in two ways. Set screw l1, contacting rocker arm IE will force the upper surface of the plate to be moved away from the lower surface thereof when pressure is applied to the rocker arm. Likewise, thumb screw I8 will cause rocker arm 15 to pivot about fulcrum I6, thereby varying the relative spacing of the upper and lower portions of the plate. It will readily be understood that diaphragms 23 and 24 will be moved with respect to each other in response to relative movement of the upper and lower portions of plate It], since these diaphragms are operatively connected to the upper and lower portions, respectively, of plate I0. Set screw l1, therefore, operates as a course tuning control while thumb screw 18 constitutes a fine tuning control for varying the spacing of the diaphragms heretofore described. Since spring plate H3 is formed in a single continuous structure, backlash and lost motion which would otherwise result from complicated springing arrangements is reduced to a minimum. In this manner, there has been provided a tuning mechanism capable of finer control and more satisfactory operation than has been attainable by tuning devices heretofore known in the art.

While a particular embodiment of this invention has been disclosed and described, it is to be understood that various changes and modifications may be made therein without departing from the spirit and scope thereof as set forth in the appended claims.

What is claimed is:

i. A mechanical tuner for tuning the .cavity resonator of electron tubes of the velocity modulated type comprising a spring plate having pair of openings therein, a clamp mounted on one section of spring plate .i-or maintaining one portion of said tube in a fixed relationship with respect to said section, a second clamp mounted on a second section of said spring plate for maintaining a second portion of said tube in a fixed relationship with respect to said second section and mean mechanically coupled to said sections for var ing the relative spacing of said sections to tune the cavity resonator of said tube.

2. A mechanical tuner for tunin the cavity resonator of electron tubes of the velocity modulated type comprising a Ushaped spring plate having a pair of openings therein, a clamp fixedly secured to the upper section or" said spring plate for maintaining one portion of said tube in a fixed relationship with respect to said section, a second clamp fixedly secured to the lower section of said spring plate for maintaining the lower portion of said tube in a fixed relationship with respect to said section and means mechanically coupled to said lower section of said spring plate for exerting pressure on upper section of said spring plate to tune the cavity resonator of said tube.

3. A mechanical tuner for tuning the cavity resonator of electron tubes of the velocity modulated type comprising a U-shaped spring plate having upper and lower sections in a substantially parallel relationship, .each of said sections being formed with an opening adapting it to receive a portion of an electron tube to "be tuned, a clamp fixedly secured to the upper section of said spring plate for maintaining the upper portion of said tube in a fixed relationship with respect to said section, a second clamp fixedly secured to the lower section of said spring plate for maintaining the lower portion of said tube in a fixed relationship with respect to said section, a rocker arm pivotally mounted on said spring plate, a first tuning means connecting the upper section of said spring plate and said rocker arm, and a second tuning means connecting the lower section of said spring plate and said rocker arm.

l. A mechanical tuner for tuning the cavity resonator of electron tube-s of the velocity mod-m lated type comprising a :U-shaped spring plate having a pair of openings therein through which tuning means 4 an electron tube may be passed, a clam fixedly secured to the upper section of said spring plate for maintaining one portion of said tube in a fixed relationship with respect to said section, a second clamp fixedly secured to the lower section of said spring plate for maintaining the lowe portion of said tube in a fixed relationship with respect to said section, a rocker arm pivotally mounted on the lower section of said spring plate, connected to the lower section of said spring plate for causing rotation of said rocker arm, and means connecting the upper portion of said spring plate and said rocker arm.

5. A mechanical tuner for tuning the cavity resonator of electron tubes of the velocity modulated type comprising a U-shaped spring plate having a pair of .openings therein through which an electron tube may be passed, a clamp fixedly secured to the upper section of said spring plate for maintaining one portion of said tube in a fixed relationship with respect o said cction, a second clam-p fixedly secured to the lower section of said spring plate for maintaining the lower portion of said tube in a fixed relationship with respect to said section, a rocker arm pivotally mounted on the lower section of said spring plate, a boss fixedly secured to the lower section of said spring plate, a thumb screw threadably' mounted in said boss for causing rotation of said rocker arm about its pivot, and a set screw threadably mounted in the upper section of said spring plate for transmitting movement of said rocker to the upper p rtion of said Spr n pl t 6. A mechanical tuner for tuning the cavity resonator of electron tubes of the velocity modulated type comprising a u shaped spring plate having'upper and lower sections, each of said sections being formed with an opening adapting it to receive a portion of an electron tube to be tuned, a clamp mounted on the upper section of said spring plate for maintaining .onepo t on of said tube in a fixed relationship if said section, .a second clamp mounted n t section of .said spring plate for maintaining a:

second portion of said tube in a fixed relationship with respect .to said section, a rocker armv pivotally mounted on the lower section of said spring plate, a first tuning means comprising a set screw threadably mounted in the upper sec.- tion of said spring plate for operatively connect ing said section and said rocking arm, a thumb screw comprising a second tuning means thread... ably mounted on an extension of the lower section of said spring plate and extending transverse to the direction or said first tuning means for operatively connecting said lower section of said spring plate and said rocker arm. --k

References Cited the file or this patent 

